Words supplied by Ballance Agri-Nutrients.
Establishing a new crop is also an opportunity to set up the pasture to be more productive in the future than the last run-out one.
“Vigorous cultivation often leads to poor pasture persistence, so pasture persistence after cropping can be challenging on soils damaged from forage cropping. Leaving the soil undisturbed actually means it can work better for you,” says Ballance Agri-Nutrients Forage Specialist Murray Lane.
“No-tillage techniques have been successfully used to grow crops for nearly 50 years, so if you’re still cultivating, maybe it’s time to change. No-till drills handle the soil as it is; it’s only the more primitive drills that require tillage to create a seedbed,” he says.
To successfully establish a crop, start in autumn with spraying to control perennial weeds such as browntop, couch, paspalum, kikuyu and Californian thistle. “You’ll kill these weeds more successfully, and if the paddock is sown into a new winter active ryegrass, it’ll produce more over winter. The weed roots and stems rot over winter, so no-till drilling of the forage crop come spring is easier.”
Slug control and drilling with fertiliser are needed for no-till drilling a brassica, chicory, plantain or clover crop. “Without cultivation, slug populations are larger and there’s no soil mineralisation. But this is easily overcome. Check with the contractor that there’s a slug bait spreader on the drill, and drill with DAP or Cropzeal Boron Boost at 150 kg/ha to give seedlings an early boost towards canopy development,” says Murray.
“Protecting the new crop seedlings is critical for success. If springtails weren’t controlled when the paddock was sprayed out, seedlings may not appear to germinate. It’s possible the more than 30,000 springtails in every square metre may have consumed them.”
Around three weeks after sowing, a side dressing of nitrogen, using a product such as SustaiN, gives the crop the vigour to outcompete weeds. SustaiN is ideal for reducing volatilisation losses, and should be applied at a rate determined by pre-crop soil testing Available N test results. If under 100, then apply 200+ kg SustaiN/ha.
Also, around the three week mark, germinating annual weeds may need to be controlled with in-crop post-emergence herbicide. “This is generally not required with no-tillage, or perhaps only for grass weed seedlings,” says Murray.
“In the absence of genetically modified crops and the BT gene, we have to keep spraying to control white butterfly, leaf miner and diamondback moth caterpillars. This can be as frequent as every three weeks in summer for brassicas. A couple of new recently-available insecticides target only the pest, and leave the predator to that pest, such as ladybirds, unaffected and able to keep working for you.”
“Finally, after harvesting the crop, when returning to new perennial pasture, drill the new seeds with DAP instead of cultivating,” says Murray.
For more support, talk to your Ballance Nutrient Specialist or Ruralco Representative.